Apparatus for rolling pipe



June "18, 1935. I w. BARK El AL APPARATUS FOR ROLLING PIPE Filed June 2, 1952 176092250915: lV/LL/HM 545K, JOHN HENRY cfi/wpr v and JHMES 0/ MHZUE/E. y: W

fie fiforneys.

Patented June 18," 1935 V UNITED STATES PATENT orFicE APPARATUS FOR ROLLING PIPE William Bark, John Henry Schmidt, and James V. Mazurie, Gary, Ind assignors to National.

Tube Company, a corporation of New Jersey This invention relates to the manufacture of pipe and particularly to an improvement in the present methods of operating pipe rolling mills and to certain details of their construction.

These mills,"which are also called plug mills,

are now made and operated so that the pipe is returned by pinch-rolls after its rolling pass, the mandrel or plug beingremoved and the rolling rolls separated to permit this. It is then necessary to turn the pipe and repass and again return it before a round shape is obtained as the rolls do not so shape the pipe with a single pass because .of their tendency to thicken its wall at their pass line. Thus it is necessary to move the pipe between the rolls four times..

One ofthe objects in the present instance is to operate a rolling mill so that a greater output of pipe results, and another is' to construct a rolling mill to include features which contribute to the effectiveness of this operation.

Ha.ving reference to the accompanying drawing which illustrates one specific form of the invention:

Figure l is a cross-sectional side elevation.

Figure 2 is a cross-section of the roll stand showing a. pass. I

Figure 3 is an enlarged detail from Figure 1.

Figure 4 is a detail.

These various figures show a rolling mill comprising a stand of rolls mounted in a housing 2 and oppositely. extending alined pipe troughs 3. A pipe pusher 4 is arranged at the remote ends of each trough for forcing pipes into the bite of the rolls, rolling pressure being maintained by screws 5 driven by a motor 6. v

A mandrel bar 1 is arranged over the righthand trough and is carried by a thrust block 8 which is reciprocable by means of a crank and arm 9. This crank is driven by a motor Ill through 180 degree arcs and may be stopped at dead center to more easily take thrusting forces.

A pin I2 is fixed to the mandrel or plug end of the bar .1, the drawing showing the two integral, although-the pin might as well be screwed or 7 otherwise fastened to the bar. This pin has a straight surface l3 of suflicient length tocarry a mandrel and a reduced portion or peripheralgroove I immediately therebeyond, the remainder of the pin being a continuation of the first surface.

A mandrel or plug I5 is slipped over the pin l2 and has conical depressions l6 surrounding both ends of its pin receiving hole. It is held on the pin by an expansible ring I! which has a conical end'iitting in one of the depressions in slight lateral play which permits this assembly. Preferably, the end of the mandrel bar' is conical so as tofit the depression in that end of the plug, otherwise should the plug have only'one end made with the conical depression mentioned it will acquire a front'and'rear which may be easily confused by a plug handler inhis haste. The

ring itself consists of two interplvoted semicircles of metal which swing outwardly.

One important feature of the above mandrel or plug is its double working surface. Ordinarily, this is shaped to work the tube when passing over it in only one direction, but here it is shaped on both sides of its center to operate as a working surface, and so far as this feature is concerned, it makes a truly double-ended plug.

A water bosh I8 is located on the left of the stand of rolls and a vertically reciprocable mandrel carriage I9 is arranged therein. This carriage is operatedby a cylinder motor 20 and when raised is in line to receivethe mandrel when the latters carrying bar is reciprocated forwardly by a half turn of the crank 9. A rest support 2| normally supports and steadies the extreme end of the pin l2, but this may be thrown out of a the way by a cylinder motor 22 to permit removal of the plug and passage of the tube. Naturally,

the locking ring I! must be removed during the plug's removal. v p

The new rolling method consists essentially in giving a tubenfo'rward and reverse passes through rolls whose rolling pressures are main tained during the second or reverse pass; Thus both passes are effective in shaping the tube instead of but one and production is doubled.

That is, instead of separating the rolls and using pinch-rolls orv other means to return the tube with a useless motion, the right-hand pusher 4 is operated to shove each singly passed pipe back into the rolls, which are of course now reversed,

so that the next movement both returns the pipe and gives it its needed second pass. The

pipe is turned, generally manually, before this a second pass in the usual manner. The structural detailspreviously described are, not here A tube rolling mill including the combination of a stand of longitudinal tube rolling rolls,

oppositely extending alined tube troughs for said stand, tube pushers arranged at the ends of said troughs remote from said stand so as to push tubes into the latter, a mandrel bar over one of said troughs and having a mandrel-carrying pin on its end adjacent said stand, a reciprocable block. for mounting-the end of said bar remote from said stand, a crank axially alined with and spaced from said block, an arm interconnecting said crank and block, a motor for revolving said arm, a double-ended mandrel releasably carried on said pin, the latter being sufllciently long to extend beyond said mandrel, a quickly removable support for the portion of said pin extend-i when said block is reciprocated to its second named position to one where it immerses said mandrel in water in said bosh.

WILLIAM BARK. JOHN HENRY SCHMIDT. JAMES V. MAZURIE. 

